Influence of row spacing on the yield of two flax cultivars (Linum usitatissimum L.)

In the period 2003-2006 we have performed block trials with two flax (Linum usitatissimum) cultivars: RBK cultivar (domestic flax population from Raztresen farm in Bela Krajina) and Laura cultivar (fibre-type-flax from the Common Catalogue of EU). The trial was carried out at the Experimental Field at the Biotechnical Faculty of Ljubljana (Slovenia). The two cultivars were sown in the first decade of April with manual sowing machine to the row spacing of 8.5 cm, 17 cm and 34 cm. Crop care was traditional. The plants were plucked at the end of the yellow maturity (the last decade of July). There was no significant difference between the average yields of stems produced at the row spacing of 8.5 cm (1.92 t/ha) and 17 cm (1.99 t/ha), but significantly the lowest yield was reached at the row spacing of 34 cm (1.52 t/ha). In the period of 4 years the average yield of stems that was reached by the RBK cultivar was 1.83 t/ha, and the one reached by the Laura cultivar was unsignificantly lower (1.79 t/ha). Compared to the average yield of the flaxseed from both cultivars produced at the row spacing of 8.5 cm (1.34 t/ha) and 34 cm (1.01 t/ha), the average yield of the seeds obtained from the 17 cm row spacing was significantly the highest (1.52 t/ha); for 0.11 t seed/ha the RBK cultivar (1.35 t/ha) was significntly more productive than the Laura cultivar. The influence of growing conditions to the yield of stems and seed was most favourable in the year of the drought (2003), when - with the cultivar RBK and at the row spacing of 17 cm - we produced significantly the highest quantity of stems (2.64 t/ha) and seeds (1.93 t/ha). We discovered that the unbranched stem of the RBK cultivar corresponds to the fibre-type-flax, the hight of plants (50 to 60 cm), absolute mass (6.3 to 6.8 g) and the yield of the seed (above 1 t/ha) show good biological capability for the seed production. Production and processing of flax should not remain just an attractive cultural and historical presentation of this activity at some turist farms in Bela Krajina (JV of Slovenia); it should also present a challenge to young farmers to find the place for this crop in organic production of food and other raw materials with the use of mechanisation and modern technological procedures. The production and processing of flax presents the possibility for increased biotic diversity of the cultural landscape and revitalization of rural areas.